Scare tactics: study shows how to instil fear but keep it fun

Whether it's a friend jumping out or a fake spider catching you off guard, most of us will have fallen victim to a scare prank at some point - and now scientists have come up with a theory for why "jump scares" are so often followed by laughter, with insights that could help concoct Halloween tricks that tickle rather than terrify.

- Linda Geddes

A popular explanation is that humor is all about surprise: successful jokes tend to set up an expectation that is overturned by the punchline.

"The problem with that theory is that we find all sorts of things funny that aren't surprising, and there are lots of surprises that we don't find funny," said Marc Hye-Knudsen, a PhD fellow and humor researcher at Aarhus University in Denmark, who led the research.

Another recent theory is that humor requires a violation in our sense of how the world "ought" to be and the almost simultaneous assessment that this breach is harmless or benign. This can take many different forms, from the violations of linguistic norms in puns and wordplay, to the social norm violations of embarrassment humor.

Hye-Knudsen and his colleagues suspect something similar may explain why the initial shock of a jump scare is often quickly followed by laughter.